Intermediate restorative material (IRM) is a zinc oxide and eugenol cement
that has been reinforced for increased strength. It is used as an intermediate
base beneath a metallic restoration and also as a temporary restoration.

a. Composition.

     (1) Powder.  80 percent zinc oxide and 20 percent
polymethyl methacrylate

     (2) Liquid. 99 percent eugenol and 1 percent acetic
acid.

b. Dispensing. The first step in dispensing
IRM is to fluff the powder for uniform density. The measuring scoop is then
filled but not packed with powder and leveled with the spatula. The powder is
then placed on the mixing pad. Finally, one drop of liquid is added for each
level scoop of powder (at a 1 to 1 ratio). After using the liquid, immediately
recap to prevent evaporation and contamination.

c. Mixing. Spatulate quickly with a
stainless steel spatula, combining half the powder with all the liquid. Add the
remaining powder in 2 or 3 increments and spatulate thoroughly. The mix will be
stiff and should be stropped (whipped vigorously) each time with the spatula for
5 to 10 seconds. This type of mixing results in a smooth and adaptable working
consistency. Mixing the IRM should be completed in approximately 1 minute (60
seconds).